RPM drop

[kcdbrian]

Today I noticed a slight dip (200 rpms) on the port engine when running at 3,000 rpm. I happens every 10 seconds or so just for a quick second, and recovers. No noticeable difference in power or sound. Any ideas?

 

[JJDebeers]

Today I noticed a slight dip (200 rpms) on the port engine when running at 3,000 rpm. I happens every 10 seconds or so just for a quick second, and recovers. No noticeable difference in power or sound. Any ideas?

Surging could be caused by a fuel restriction somewhere. Check the fuel system (dip tubes, lines, filters, tank vent) to ensure there are no restrictions.

Personally, I'd check the fuel system before I got into the ignition. But others may say otherwise...

Thanks,
JJ

 

[buick430]

could also be a faulty tach mine started doing that a couple hours before it read that I was idling at 350RPM

will

 

[JJDebeers]

could also be a faulty tach mine started doing that a couple hours before it read that I was idling at 350RPM

will

Great point. 1st confirm that the tach is reading accurate. If it isn't, then check the fuel system.

-JJ

 

[kcdbrian]

Thanks guys - greatly appreciated! Have a great weekend.

 

[kcdbrian]

It's still surging over 2,500 RPM. It starts and runs fine and operates normally up until it hits 2,500. - I changed the small fuel filter before the carb, but not the fuel/water separator....yet. It only seems to surge until load and high RPM. It fluctuates about 200/300 rpm

 

[fastjeff]

You might have a bad plug/ plug wire. Pull them out and note the color of each.

Jeff